Here is the exhaust tip.
This is the top, inner wall shown before it was welded together. there is a sketch below it to show how it will come together.
This is the above picture welded and metal finished.
Here is the exploded view of all of the inner panels. (The bottom has been started)
All 4 panels welded ad metal finished.
No picture, but the 4 panels were then welded together to make a box. an outer skin was made and the whole assemble was welded together to make the complete exhaust tip. (Shown upside down to view the inside detail)
(Shown right side up as it would be installed in the car)